Based on the magic enchanted within the Glyphed Oaken Branch, its delivery to the Cenarion Circle in Darnassus is the next step the tauren druid sought. Seek one of the druids there for assistance.
The lifeless hand of the tauren druid clutches a surprisingly healthy looking oaken branch. Examining the branch reveals glyphs of a druidic nature carved into the bark.
As you grasp the branch, you notice it is warm to the touch, more than it should be. The image of the Teldrassil tree enters your mind - Darnassus specifically - and the words "Cenarion Circle" are on the tip of your tongue. It would appear that the suggestion of where to take the branch has been placed within it.